1. Field of The Invention
The present invention relates to plates, especially made of a brittle material of the glass type, which are equipped so as to be fastened to supports via connecting elements.
2. Discussion of The Background
Such plates are intended especially to equip heating means, such as radiators, convectors, etc., without, however, the present invention being limited to such an application. Thus, the fastening of double-glazing or laminated-glass plates may be mentioned, and also the production of walls or of furniture made of glass substrates.
These plates must therefore have holes at the fastening points. The plates may be strengthened, especially by thermally or chemically toughening them, in order to obtain the mechanical strength (and where appropriate the thermal resistance) that is required. The holes must then be made before the heat treatment.
PCT International Application WO-A1-01/09459 discloses a fastening element for double-glazing plates, said element consisting of a threaded bolt having, at a front end thereof, an expansion cone onto which a ring-shaped expansion element is slipped for the purpose of expansion in a hole in the rear glass plate, said hole being back-tapered in the region of its bottom.
Such a device has the drawback that, while the glass plates provided with holes having such back tapers are being heat treated, high stresses are created in the region of the fillet that joins the bottom of these holes to the frustoconical side wall emerging in the surface of the glass plate and flaring out toward the bottom of the holes. These high stresses may result in defective plates that have to be scrapped after the heat treatment or in which, while they are being mounted or subsequent to their use, faults are developed such as cracks.
Another drawback of this known arrangement is that, once the plate has been mounted, it is only with very great difficulty that it can be demounted, with a high risk of damaging or even breaking it.